fix: sort segments if ram_only_header is used

There are a few scenarios that segment sorting is required.
This is (as for now) a zephyr-case scenario only, where
flash section can be created during in-between ram linking.
Without segment sorting, flash segments will overlap and ELF won't
be created.

Signed-off-by: Sylvio Alves <sylvio.alves@espressif.com>

esptool/bin_image.py

@@ -352,6 +352,11 @@ class BaseFirmwareImage(object):
         irom_segment = self.get_irom_segment()
         return [s for s in self.segments if s != irom_segment]
 
+    def sort_segments(self):
+        if not self.segments:
+            return  # nothing to sort
+        self.segments = sorted(self.segments, key=lambda s: s.addr)
+
     def merge_adjacent_segments(self):
         if not self.segments:
             return  # nothing to merge

esptool/cmds.py

@@ -1039,8 +1039,6 @@ def elf2image(args):
         args.chip = "esp8266"
 
     print("Creating {} image...".format(args.chip))
-    if args.ram_only_header:
-        print("ROM segments hidden - only RAM segments are visible to the ROM loader!")
 
     if args.chip != "esp8266":
         image = CHIP_DEFS[args.chip].BOOTLOADER_IMAGE()
@@ -1076,6 +1074,10 @@ def elf2image(args):
         image.elf_sha256 = e.sha256()
         image.elf_sha256_offset = args.elf_sha256_offset
 
+    if args.ram_only_header:
+        print("ROM segments hidden - only RAM segments are visible to the ROM loader!")
+        image.sort_segments()
+
     before = len(image.segments)
     image.merge_adjacent_segments()
     if len(image.segments) != before: